Chapter 12 Avaya P330 Layer 3 Features
IP Fragmentation and Reassembly
IP Fragmentation and Reassembly Overview
The P330 supports IP Fragmentation and Reassembly. This feature allows the router to send and receive large IP packets where the underlying data link protocol constrains MTU (maximum transport unit).
IP fragmentation involves breaking a datagram into a number of pieces that can be reassembled later. The IP source, destination, identification, total length, and fragment offset fields, along with the “more” fragment and “don't” fragment flags in the IP header, are used for IP fragmentation and reassembly.
IP Fragmentation works as follows:
•IP packet is divided into fragments
•each fragment becomes its own IP packet
•each packet has same identifier, source, destination address
•fragments are usually not reassembled until final destination
IP Fragmentation/Reassembly CLI Commands
In order to... | Use the following command... |
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Clear the fragment database and | clear fragment |
restore its defaults |
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Set the maximum number of | fragment chain |
fragments that can comprise a |
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single IP packet |
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Set the maximum number of | fragment size |
fragmented IP packets, destined for |
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the router, to reassemble at any |
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given time |
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Set the maximum number of | fragment timeout |
seconds to reassemble a |
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fragmented IP packet destined for |
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the router. |
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Display information regarding | show fragment |
fragmented IP packets that are |
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destined for the router |
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154 | Avaya |
